Envelope flap opening device



Feb. 2, 1954 i J. w. BACH ,6 8,

ENVELOPE FLAP OPENING DEvIpE I Filed Dec. 7, 1950 2 Sheets-Sheet 1 F1. 5 1D. //2 M w/ z'tfm ATTORNEY Feb. 2, 1954 J. w. BACH 2,668,053

ENVELOPE FLAP opzumc: DEVICE v I Filed Dec. 7. 1950 2 Sheets-Sheet? VENTO I \j /mL/l/ fem 4-09 ATTORNEY Patented Feb. 2, 1954 ENVELOPE FLAP OPENING DEVICE John William Bach, Port Chester, N. Y., asslgnor to Pitney-Bowes, Inc., Stamford, Conn., a corporation of Delaware Application December 7, 1950, Serial No. 199,712

19 Claims. 1

This invention relates to the art of handling envelopes.

In mailing room and in general procedure, where many identical pieces of mail matter are handled, the insertion of the mail matter is expedited when the envelopes are received with flaps opened.

Envelopes are furnished by manufacturers with the flap folded firmly against the body, and, when flap opening is performed by hand, it is obviously tedious and expensive.

The present invention provides a machine for performing the flap opening operation automatically and depositing the envelopes as so opened one upon another.

An important feature of the present invention is the provision of an envelope opening machine of extremely simple construction and operation, which is at the same time capable of adjustment for envelopes of various depths and which is thoroughly reliable and positive in its action.

Another object of the invention is the provision of a simple, direct method by which the flap opening is accomplished. It is a feature of the invention that this operation involves merely feeding of an envelope edgewise in one direction, flap edge foremost, along a curved path with the flap on the convex side until the flap escapes past a stripper member, then producing relative movement between the stripper and the envelope transversely of the flap crease so that the stripper catches beneath the flap and eventually folds the flap backward and lays it out flat.

In the particular form of the invention illustrated, the relative movement between the envelope and stripper is brought about by reversing the direction of movement of the envelope after The progressing of the envelope in a curved path may also be considered as a bowing or buckling of the envelope, combined with a deflecting action which predetermines the direction of buckle so that the convex flap face will be to-- wards the stripper, thus insuring a sharp separation of the flap from the envelope body to permit the flap to be readily caught by the stripper.

The invention also provides as a feature thereof the method and arrangement whereby the above mentioned reversal in envelope feed is ac complished in a unique fashion by transferring the feed from one set of continuously rotating rollers to another. Consequently no movement reversals, other than of the work itself, are needed. This makes possible th high speed of operation achievable by the device since inertia effects are avoided.

Still another important feature of the invention resides in the direct solution provided for at least two distinct problems relating to the handling of the paper envelopes. Whereas the stopping of the envelope at high speeds would involvea tendency to mark the edge, and whereas the transfer of the envelope from the forward feed to the withdrawal feed would depend upon the resiliency of the envelope resulting from the material used in its manufacture or from the surrounding atmospheric conditions such as humidity, the adverse effects of both factors are obviated by the unique expedient of providing a resilient end stop for engaging and arresting the edge of the incoming envelope, and for giving it an impetus in withdrawal direction.

Since certain folding machines now in use provide power driven pinchrollers suited to the flap opening operation, and also include such devices as a feeder, a collector and stacker for finished work, a motor for power operation, etc., it is extremely economical and advantageous to provide an attachment for such machines which would readily convert them for envelope opening work.

Another object of the invention, therefore, is to provide an attachment of small weight and few parts which can be mounted upon a four roller buckle type folding machine, or upon any machine providing at least three parallel con-' tacting feed rollers, for converting the same into an envelope opening device.

Additional features and advantages will hereinafter appear.

A preferred embodiment of the invention is shown in the following drawings, wherein:

Fig. 1 is a partial vertical, longitudinal section of an envelope opening machine according tothe invention, the same being illustrated in the form of a folding machine employing an envelope opening attachment;

Fig. 2 is a fragmentary detail elevation to an enlarged scale and. represents essentially the face view of the attachment which converts the folding machine into an envelope opening machine, together with the immediately adjacent portions of. the folding machine as seen from the right and looking towards the left in Fig. 1. The view is taken substantially on line 2 2 of Fig. 3;

Fig. 3 isa section taken on line 3-3 of Fig. 2

3 with the latches and their mountings omitted for purposes of clarity, and also including the roller mechanism of the folding machine;

Fig. 4 is a detail section of the attachment taken on line 4-4 of Fig. 2;

Fig. 5 is a detail section taken on line 55 of Fig. 2 and illustrating particularly the latch means for retaining the attachment in place on the folding machine;

Figs. 6, 7 and 8 are schematic views illustrating successive steps in the process of opening the flap of an envelope, and in the progress of an envelope through a machine made according tothe invention;

Fig. 9 is a perspective view showing the rear face of the usual mailing envelope before opening the flap; and

Fig. 10 is a perspective viewshowing th'erear face of the envelope of Fig. 9 after treatment by the flap opening machine.

Referring to the drawings in detail, the invention described herein relates to envelope handling and isdescribed in detail with particular reference to an envelope-flap opening machinewhich-takes the form of a four roller buckle type sheet folding machine and an envelope flap opening attachment therefor.

Iii-Fig. 1 is illustrated a sheet folding machine H39"- on which has been-mounted the envelope fiapopening. attachment III The folding machine includes an envelope supply holder and guide 102, a feed mechanism IS I of known construction 'for'removing one'envelope at a time from the supply holder I92 and thrusting the same forward to be operated upon, and a short guide plate I05 bridging the gap between the feeder I94 and the folding rollers. In'the four roller buckle type folder these rollers normally consist of a central roller I08, an upper roller I II], 'a rear roller I I2, and a lower roller I I4. The central roller I08 rotates clockwise as. seen in Fig. 1 under the influence ofa power source (not shown) and the other rollers are resiliently urged against roller I98 in a known manner. When used in a sheet folding operation, the rollers .normally cooperate with upper buckle chute 6' having buckle stops II8,i and lower. buckle chute I20 which has buckle stops I22,'to provide trans.- verse folds in work sheets- The buckle stops I I8 and I22 are normally adjustable about the axis of shaft I2 3 to lengthen or shorten the corre-.- sponding buckle chute, and-thus to provide folds of different lengths. The lower buckle stop..I22,n furthermore, .has a zero position,. shown in Fig. l .in which it engages a deflector plate. I24 and moves the same into deflecting positionsuch that any piece issuingfrom betweenrollers I08,--II2 is directed to the nip of .therollers I38, I I4 and fed therebetween to avoid a second foldl Pieces issuing from between rollers I98, II4-are stacked. on and transported by the stackingbelt I26.

As shown. in Fig. 1, the folding machine is so arranged that the upper buckle stop H3 canbe adjusted back out of the way, and the upper: buckle chute can be swung rearwardly to open up the machine for the clearing of jams and the like. With the foldingmachine thus adjusted; it is ready for conversion toan envelope flap opening machine by the placing of the:rattachment Ill therein.

The machine I09 isshown asincluding-trans versely extending members I28 and I38; The upper member or bar I28 is a 'structural'member which extends across the machine; while the lower" members I3Ilare stopstuds whichnormall'ypo sition the end of the upper buckle chute I I6 when the same is moved to operative position. At either side of the machine is also provided a pivoted spring pressed latch I32 including manually engageable means I34 for releasing the same against the spring pressure. The latches I32 are intended normally for retention of the end of upper buckle chute II6--in-aoperative position against the stud 30..

The envelope flap opening attachment I9 which is: applied to the folding machine includes notched portions I2 at either end of the attachment, which notched portions are adapted to engage with :the. locating studs I38. Hooks I i-44 are also included for "engaging the bar I28 and for supporting the attachment thereon. Laterally projecting ears I5I5 and engaged by latches I32to"retain the attachment in an operating position: As seen particularly in Figs. 2 and 4, the attachment I0 preferably consist of sheet metal stampings and includes a guide plate I6 for engaging the leading edge of an incoming.. envelope and .directing the same upwardly. .The guide plate is mounted on a. frame member. or... bail. I 8 which includes a transverse member. 26... extendingv across the machine and rearwardly. and downwardly sloping arms 22. The-frame or bail-I8 provides the locatingnotchesIZ and is firmly attached to the support hooks I l.v Asclearly seen in Fig. thetransverse member 20 slopes upwardly and rearwardly and is connected at its upper edge to a plate-24-which is bent to form an angle 26 such. that .the-upper,end-..ex--- tends substantially vertically.

A vertical slot 28 in plate 24 receives a bolt.30ethreadedly connected with a depending .plate 32. Theplate SZtogether with plate I6 and the ad-- jacent portions of .theeplate 24;-form1a.blind;;. deviated chute whose length. may be-adjusted by sliding the bolt'3B up ordown in .theslot-28,-- and using the bolt-3e toc1amp:the--plate"32 to the plate-2l-at any desired location. For .this purpose, an enlarged knurled: head '34 isprovided. on the-bolt3fl for ready manipulation. Mountedfion the plate 32 I and extending "across the end of: the chute formed bythe-plates-uZfl-and32 is a spring finger 38.- The spring. finger '36 preferably)" extends through-opposedslotsin the plates 24's and 32 .asshown in Fig.- Landmore .than onc of such fingers 35 may beemployed, if.-desired-, positionedat various locations across the plate 32.

The outer ends of'zarms .22 provide mountings. means for a shaft 38 on which is'pivotally sup+ ported a stripper plate ifi'with itsfree edge located near the'member 20 and. is movableto. raised or lowered positionby-pivoting.of.the: plate 40- about theaxis of :shaftx38i The slotted: sector 42, Fig.3, is integrally connected toratheeplate 48 for-movement therewith. Arclam'pin stud Mthreaded in a reinforcing pad'23 on arm"- 22 adjacent the sector 42,-and passinglthrough the slot therein, is provided for'clampingthe plate: 40 in any desired pivotal position. By" means of this adjustable mounting, the mecha nismcan beadjusted 'ito accommodate envelopes of-diffe'rent depths-as well as envelopes'having difierent fiap sizes.

The relationshipof the parts described above is such that an envelope feeding straightout' from the nip of rollers I08, III will be deflected" upwardly slightly by the stripper member lfl in" cooperation with the guide plate I (L- Since the most effective arrangement for the stripper surface all :isnearly perpendicular to thepath of the: envelopejthereis some danger that the leading edge of the envelope might be caught by the lower surface of the same and fail to slide off, thereby'causing a jam. In this respect therefore, the guide plate I6 may be considered essentially'a fender portion of the stripper designed fordeflecting contact with the incoming envelope. The plate 32 is so arranged that, after leaving the stripper, the leading edge of an incoming envelope will be further deflected thereby in the same direction. This action, possibly in cooperation with some restraint by angle 26 against the opposite surface of the envelope will cause a bowing action which tends to spread the free edge of the flap sharply away from the envelope body, and put the flap in position for readystripping during the withdrawal pass. Preferably the parts will be arranged as shown in the drawing so that deflecting contact of the leading edge of the envelope with plate 32 occurs substantially before the trailing edge of the incoming flap is clear of the stripper 4B. This will insure that the flap will escape forcibly from the stripper and that on the return or withdrawal pass of the envelope there will still be a certain amount of bowing thereof with consequent projection of the flap, at the time the flap edge first comes to a position where its engagement with the strippe 40 is imminent. I

The operation of the device of this invention is best illustrated in Figs. 6, 7 and 8 from which it will be clear that a plurality of envelopes 46 having flaps 48, folded in the normal way as shown in Fig. 9, are stacked in the supply holder or guide I02 with flap creases at the bottom and with the flaps facing away from the machine.

When the machine is started the feed mechanism I84 separates the flrst'envelope 45 and projects.

the same, flap crease first, across the guide plate I98 and into the nip of the rollers I08, IIiI which continue to feed the envelope onward and against the guide plate I6 which directs the leading edge upwardly and into the chute formed by itself and the plates 24 and 32, and then around the angle 26 to the position shown in Fig. 6. This concaving of the front face of the envelope results in an accentuation of the separation of the flap 43 from the rear surface of the envelope and causes the same to project sharply so as to be conveniently stripped. In Fig. 6 the flap has just escaped forcibly over the edge of stripper 49. The envelope then proceeds to strike up against the spring finger 36, deflect the same, and then to buckle a little further as the rollers IE8, Ill! complete the feeding operation and the trailing edge of the envelope leaves their discharge. At this instant friction of the roller I98 with the trailing edge of the envelope carries the same across towards the nip of the rollers I08, H2 at which time the envelope 45, due to its inherent resiliency, tends to straighten out so as to thrust its bottom edge into the nip of the latter roller pair. As soon as rollers I08, II2 make driving contact with the envelope they withdraw the same downwardly causing the stripper 40 to catch under the flap 48 and commence the straightening of the flap as shown in Fig. 7. Continued feeding by the roller pair I68, I I2 causes the bottom edge of the envelope to strike the deflector I24 and to be directed thereby into the nip of roller pair Hi8, II4, also as shown in Fig. '7. Thereafter the envelope 46 is fed continuously out from between the rollers, the crease E which defines the inner edge of the flap 48 being first straightened by stripper 49 and thereafter, as shown in Fig. 8, ironed out both by roller pair I08, H2 and rollerpair I08, H4. The envelope 46 is then thrust out onto the stacking belt I26 in the open flap condition illustrated in Fig. 10,

and carried to a storage location for completed.

work.

Theironing process to which the crease 50 is subjected largely removes the set which the en- I that the same is in condition for ready insertion of the contents either by hand or by machine.

An adjustment of the machine for any given depth of envelope within its capacity can be made by. slowly feeding a sample envelope just past the position of Fig. 6 so that the trailing edge has barely left the roller pair I os, I Ill. The bolt 38 is then loosened and slid in the slot 28 until the envelope is engaged and slightly buckled by the spring finger 36 which isalso deflected. The parts are then clamped in this position. The stripper 40 is set low enough to provide clearance between itself and the bottom edge of flap 48, and is clamped in this position by means of clamping stud 44.

Spring finger 38 is an important feature of the invention and provides a gradual arresting action against the leading edge of the envelope which avoids marking of this edge when the envelopes are being projected upwardly with.sub. stantial force during high speed operation of the machine. This, however, is not the sole function of the spring 36 which contributes a very desirable, uniform ejecting action tending to insure a firm and early grasping of the lower envelope edge upon its transfer to the withdrawal rollers I98, H2, and thus to provide a.

sure and reliable action of the machine regardless of variations in the resiliency of the envelope itself, whether such variations are due to changes of atmospheric conditions such as humidity, or to differences in the materials of which the envelopes are made.

The invention also embodies a nove1 process for opening envelope flaps which appears from the showing in Figs. 6 to 8 and the description pertaining thereto. This process includes bowing the envelope with face inward so that the flap is caused to project, and then drawing the projecting fiap over a stripping edge to open the flap fully. The step of ironing the crease is also preferably added for rendering the opening action more permanent. The process of this invention also includes the steps of moving an envelope 4B in one direction with its flap surface to-. Wards a stripper member 4:], until the flap has escaped past the stripper, and then producing relative movement, generally transversely of the,

envelope crease between the envelope 46 and stripper 40 so as to lay the flap out straight against the stripper.

In a more specific aspect the method of the in V vention also includes feeding the envelope 4G in one direction across a stripper 40 by a roller pair,

e. g. rollers 08, I I0, arresting the leading edge of the envelope as by the end of the chute,vor 4 lower edge to transfer to and to thrust itself into I the nip of a pair of adjacent Withdrawal rollers. e. g. rollers I08, IIZ.

Still anothervaspect of the methodof the in-.

acetate vention involves certain of-"thesteps above out lined 'asapplied'to the operation of a'iour roller buckle type folder-for envelope fiap'opening pur poses- While the invention has been particularly'de scribed in theformof an attachmentfor use in connection with a foldingmachine: it "willbe" readily appreciated that the-elements and prin which do not necessarily enter into the envelope flap opening operation; e. g. the buckle chutes lls and -liilythe--buckle stops H8 and [22, de-

doctor 24 and lower roller "I M. The invention accordingly-includes machines of this character as well as the specifically described attachment fora folding machine.

While-in order to comply with the-statute the invention is described in language which'is rather."

specific as to structural features and arrangements, it is to be understood that the invention is not liin'itedto the-specific details shown, but'that the means herein disclosed comprises the pre-' ferred of several modes of putting theinvention into efict, and the invention is therefore claimed inanyof its forms or modifications withinzthe scope ofthe language'employed in the appended claims.-

Having described the claimedis:

1. An envelope flap opening machine comprising-a'deviated guide chute; means for thrusting an'envelope; 'fiap edge foremost," in one direction into said chute whereby the envelope is bent to space the free end of the flap from the body of the envelope; aflap stripping member located at the: convex side of the chute positioned to come between the convex faceof an envelope in the chute and the spaced free end of the flap; means arresting the envelope in the chute after the stripping member has been passed by the edge of tlie flap and means 'for withdrawing the envelope from thechute "m the"opposite-direction;

invention, what is Whereb y the stripper lays the flap backs-Way" irom the envelope' body,

2; An'envelope'fiap opening machine compris ing 'a deviated guide chute; means for thrusting anenvelope,-fiap edge foremost, in one direction in'to said chutewhereby the envelope is bent 'to space-the flap from the body of the envelope;

means for- 'withdrawing the envelopefromthe' chute in the opposite direction Wherebythe stripper lays the flap back away fromthe en VelOpe body; and rollers forfeeding the envelope out in opened condition in a direction perpendic ula'r' tdthe fiap' crease and for simultaneously ironing l the flap crease to reduce the closing tendency thereofi 3." An envelope flap opening machine comprisingafeed rollers a pair of" which insert sin-envelope;- flapi edge ioremost'in one direction and a pair of which withdraw the same in generally the opposite-direction; a deviated guide chute into which an envelope thrust by said insertion rollers'iiandbent tc space thefree end of the'flap from the body of the envelope; a flapjstripping member located at the-con'vex side of "said chute positioned to come between-"the convex face of an envelope in the chute-and the spaced free-"- endoi'the'flap; and means for transferring'the trailing edge pfan' envelope in "saidchute' from r the discharge of the -insertion rollers to the nip? of'the withdrawal rollersso that the flEpJOfthjC envelope is laid back" by engagement with the" strippermember.

4: An envelope flap openingmachine comprise ing'feed rollers a pair of which insert anjen velope; flap edge foremost, in onejdirection'and' a'pair of 'whichwithdraw the same ingenerall'y the"opposite'direction; a deviated guide chute] into which an envelope is thrust by said insertionrollers and bent to'space the free end of theffiap'i from the body of the envelope; 'a'fiap stripping" member located; at the convex sideof sai'cl'chute positioned to come between the convex face of an envelope in the chute'and'thespaced "freeend' or" the flap; and means for transferring the trail ing edge of an envelope in said chute from the discharge cf the insertion rollersto the ni'pof the withdrawal rollers so that the flap of the en-' velope is laid back by engagement with: the stripper member, saiddast'n'amed means being; adjustable to accommodate envelopes of different depths.

5. An envelope flap opening machine 'compris ing iced rollers a pair'of 'whichin'sert 'an -envelope, flap edge foremost, in one directionand" a pair of which withdraw thesamein generally;

the opposite direction; a deviated guide chute into which an envelope is thrust by said insertion rollers and bent to space'the free end of the flap from the body of the envelope; a fiapstripping member located .at the convex side of "saidl chute positioned to come between the convex face of an envelopein the chute and the spacedrfree endof the flap; and means for transferringthe trailingedge of anenvelope 'in said chute from the-discharge of the insertion rollersto the nip of the withdrawalrollers so that the flap of the envelope is laid'bac-k by engagementwith; the stripper member, including resilient means located adjacent'the end of said chutefor engagementwith the leading edge of an envelopethrust into the chute. I

6. An envelope flap opening machine comprising three feed rollers the first of which: cooperates with one of the others to provide aninsercated at the convex sideof said chute-positioned to come between the convex face. of an envelope: in thech'ute andthe spaced free end of the flap;

and-means for transferringrthe trailingedge ofan envelope in said chute from the discharge of the insertion rollers to-the nipof the withdrawal Y rollers.

'7. An envelope flap opening machine comprising three feed 'rollersthe first of which cooperates with one of the others to provide an insertion roller pair for feeding an envelope, flap edge foremost, in one direction, and with thethird roller'to provide a-withdrawal roller pair for feedingth'e envelope in generally theopposite direction; a deviated guide chute into which. an envelope is thrust by said insertion rollers -andbent to space the free edge of the flap from tioned to come between the convex face of an envelope in the chute and the spaced free end of the flap; and means for transferring the trailing edge of an envelope in said chute from the discharge of the insertion rollers to the nip of the withdrawal rollers including resilient means located adjacent the end of said chute for engagement with the leading edge of an envelope thrust into the chute; said last named means being adjustable to accommodate envelopes of different depths.

' 8. For use with a buckle type folder having a plurality of rollers constituting a projection pair and a withdrawal pair, an attachment for conthe folder with the chute entrance adjacent the a discharge of said projection pair and the nip of said withdrawal pair.

9. For use with a buckle type folderhaving a plurality of rollers constituting a projection pair and a withdrawal pair, an attachment for converting the folder to an envelope flap opening machine, comprising a frame means on the frame'providing a blind deviated chute having an entrance, and having an opening at its convex side; flap stripper means on the frame adjacent said opening and so related to the chute as to come between the convex face of an envelope in the chute and the free end of the flap of such envelope which has becomespaced from the envelope face due to its buckled position in the chute; means for adjusting the effective length of said chute in the direction of envelope travel; and means for mounting the frame on the folder with the chute entrance adjacent the discharge of said projection pair and the-nip of said withdrawal pair.

10. For use with a buckle type folder having a plurality of rollers constituting a projection pair and a withdrawal pair, an attachment for converting the folder to an envelope flap opening machine, comprising a frame; means on the frame providing a blind deviated chute having an entrance, and having an opening at its convex side; flap stripper means on the frame adjacent said opening and so related to the chute as to come between the convex face of an envelope in the chute and the free end of the flap of such envelope which has become spaced from the envelope face due to its buckled position in the chute; means for adjusting the effective length of said chute in the direction of envelope travel; means for adjusting the position of the stripper means along the chute in the direction of envelope travel, and means for mounting the frame on the folder with the chute entrance adjacent the discharge of said projection pair and the nip of said withdrawal pair.

11. For use with a buckle type folder having a plurality of rollers constituting a projection pair and a withdrawal pair, an attachment for converting the folder to an envelope flap opening machine, comprising a frame; means on the 1Q frame providing a deviated chute having an entrance, and having an opening at its convex side;

7 a flap stripper plate pivoted on the frame and having an edge adjacent said opening and so related to the chute as to come between the convex face of an envelope in the chute and the free end of the flap of such envelope which has become spaced from the envelope face due to its buckled position in the chute; means for adjusting the effective length of said chute in the direction of envelope travel; means for releasably holding the stripper plate in adjusted position about its pivot for thus positioning said edge at any desired location along the chute in the direction of envelope travel; and means for mounting the frame on the folder .with the chute entrance adjacent the discharge of said projection pair and the nip of said withdrawal pair.

12. For use with a buckle type folder having a plurality of rollers constLtuting a projection pair and a withdrawal pair, an attachment for com verting the folder to an envelope flap opening machine, comprising a frame; means on the frame providing a blind deviated chute having an entrance, and having an opening at its convex side, said means including a bent plate forming one side of said chute and a second plate adjustably mounted on said first plate and forming a. portion of the other side of the chute, and means defining the blind end of the chute and carried by said second plate; flap stripper means. on the frame adjacent said opening and so related to the chute as to come between the convex face of an envelope in the chute and the free end of the flap of such envelope which has become spaced from the envelope face due to its buckled position in the chute; and means for mounting the frame on the folder with the chute entrance adjacent the discharge of said projection pair and the nip of said withdrawal pair.

13. For use with'a buckle type folder having a plurality of rollers constituting a projection pair and a withdrawal pair, an attachment for converting the folder to an envelope flap opening machine, comprising a frame; means on the frame providing a deviated chute having an en-' trance and having an opening at its convex side; flap stripper means on the frame adjacent said opening and so related to the chute as to come between the convex face of an envelope in the chute and'the free end of the flap of such envelope which has become spaced from the envelope face due to its buckled position in the chute; means for mounting the frame on the folder with the chute entrance adjacent the discharge of said projection pair and the nip of said withdrawal pair; and resilient envelope edge contacting means mounted at the opposite end of said chute from said entrance.

14. For use with a buckle type folder having a plurality of rollers constituting a projection pair and a withdrawal pair, an attachment for converting the folder to an envelope flap opening machine, comprising a frame; means on the frame providing a deviated chute having an entrance, and having an opening at its convex side, said means including a bent plate forming one side of said chute and a second plate adjustably mounted on said bent plate and forming a portion of the other side of said chute, and spring fingers carried by said second plate and extending across said chute to provide a resilient envelope edge contacting means substantially defining the end of the chute; flap stripper means on the frame entering said opening and so related to the. chute as to. come between. the. convex face of an envelopein the chute and" the'. free end of the flap of such. envelope which has become spaced from the envelope faceldue to its buckledjposition in the chute; and .means for mounting the frame on the folder with the chute entrance adjacent the discharge of. said projec- 'jtlOl'l pair and the nip ofsaid withdrawal pair.

15,"'For use with a buckle type folder having a plurality of rollers constituting a projectionpair :and a withdrawal pair, an attachmentfor, con- -verting the'folder to'an envelope flapopening machine, comprising a. frame; means on .the frame providing a blind deviated chute having an entrance, and havingan opening .at its convex ---side;"flap stripper means on the frameadjacent "said opening and so related to the vvchuteasto -cn1e betweenthe convex face of an. envelopelin the-chute and the free end of theffiap of such envelope which has become spaced from. theenvelope facedue: to its buckled. .positionin ...the chute; resilient ,envelope edge contactingmeans for "determining substantially .the end of. .said "chute; means for. adjusting .the position of said --resilient 'means'for determining the effective *lengthof said chute in the direction of envelope travel; and means for, mounting the frame onthe *folder with the chute entrance adjacent the discharge of said projection pair and the nip of said" withdrawal pair.

16."The' method .of opening an envelope flap "which ."COIIlPlIiSGS the steps of moving the en- 've1ope,-'flap edge foremost in one direction; deflecting the envelope somewhat from its. normal path by a relatively stationary stripper member :pressedagainst the'fiap surface thereof; during continued movement of the. envelope, further .defleeting the leadingedge of the same. from the stripper determined path; stopping said motion "when-the flap has cleared the. stripper; and then moving theenvelope in a generally reverse directiorrsuch-that:the surfaceof the envelope is maintained, in'proximity. to the stripper and the flap is caught and straightened by the stripper as'the envelope passes.

17; The method of continuously opening .en- "velope'flaps which comprises feeding each .en- *velopefflap edge foremost, in one directionby means of a pair ofcontinuously rotating rollers;

arrestingtheleading edge of said envelope. ata

location such that the envelope is slightly buckled when; fully fed from between said rollers; simultaneously deflecting the travel of said. envelope so that-"therlatter is compelled to buckle in. a predetermined direction with the flap on the con- .vex surface and. urging. the. trailing- .edgelof. said envelope. towards a pair of. continuously-rotat- .,ing rollers rotating in. a withdrawal direction,

.wherebythe envelopes trailingedge snaps. into the nip of. said second pair of rollers when freed .bythe firstepair; and stripping the flap/to an opened -.-position-as theenvelope is withdrawn from said-location by said second. pair of rollers.

. 18.. Themethod .of' continuously opening envelope fiaps using a four roller buckle folder having. a center. roller and three outer rollers, which comprisesplacing adefiector between one-pair of outer rollers; feeding each envelope, flapsurface towards thecenter roll and flap edge foremost, between the center rolland the remaining outer rollotherthan said pair; arrestingthe leadingedge of said envelope at a location such that .theenvelope. is-slightly buckled when fully fed; from between saidcenter roller andtsaid remaining roller; simultaneously deflecting the travel of said envelope so that the latter is compelled to buckle towardsthe adjacent roller-pf saidpair, of outer. rollers andwith its flapsurface convexed,. whereby when the trailingedge ofathe envelope isfree ofsaidremaining roller, it-will be carriedalongby saidcenter roller, will-snap into the nip formed. between said. central roller and said adjacent roller: and w-ill bevfed in.:a withdrawal.direction. thereby; and stripping: the flap to open position aslthe envelopeds withdrawnv from said location.

19$ Themethod of-opening an envelopelflap whichcomprises moving-an envelope, flap edge foremost,.in asubstantially predetermined curved pathin one.direction, andguiding and confining the stripper; and. then. moving. the envelopein ,a reverse direction .in said curved path=so that the flap is caught and laid-back by. the stripper.

JOHN WILLIAM BACI-I.

"References Cited in the'file of this. patent UNITED STATES PATENTS h Number *Name Date Re..15;385 :McCarthy June 13, 1922 ..1,803;049 "Bou-ton Apr. 28, 1931 12,423,146 Herbert July 1, 1947 

